CN112690041B

CN112690041B - Method and system for controlling illumination level of user interface light emitting element of electrical device

Info

Publication number: CN112690041B
Application number: CN201980058040.2A
Authority: CN
Inventors: B·H·尼兹特洛伊
Original assignee: Gillette Co LLC
Current assignee: Gillette Co LLC
Priority date: 2018-09-05
Filing date: 2019-08-28
Publication date: 2023-07-28
Anticipated expiration: 2039-08-28
Also published as: JP2021535569A; US20200077481A1; EP3847872B1; EP3847872A1; WO2020051036A1; US10602595B1; CN112690041A; JP7078802B2

Abstract

The illumination level of the light emitting element for the user interface of the electrical device is controlled by a processor that drives the light emitting element with a Pulse Width Modulation (PWM) or other type of control signal that is calculated based on: a) A signal corresponding to a desired time-varying illumination level of the light emitting element to be perceived by a human observer, and b) a nonlinear sensitivity relationship between an actual illumination level and a resulting illumination level perceived by a human eye, wherein the corresponding signal comprises an increasing sinusoidal-based ramp function and a decreasing sinusoidal-based ramp function.

Description

Method and system for controlling illumination level of user interface light emitting element of electrical device

Technical Field

The present disclosure relates generally to electrical device user interfaces, and more particularly to such user interfaces that include light emitting elements such as Light Emitting Diodes (LEDs).

Background

The light emitting elements of the user interface of the electrical device may be used to communicate one or more aspects of the operational status of the device to a consumer. In other words, the illuminance level of the light emitting element indicates the operation state of the electrical device. In the case of LEDs, one typical method for adjusting the LED illumination level is to turn the LED on or off or by flashing the LED. For some consumers, such abrupt changes in the illumination level of the light emitting element may be uncomfortable.

Disclosure of Invention

One aspect of the invention relates to a system for controlling an illuminance level of a light emitting element of a user interface for an electrical device, the electrical device comprising a processor and a memory in communication with the processor, the memory for storing instructions that when executed by the processor cause the system to: information defining a signal corresponding to a desired time-varying illuminance level of the light emitting element to be perceived by a human observer is stored, wherein the corresponding signal comprises an increasing sinusoidal-based ramp function and a decreasing sinusoidal-based ramp function. The stored instructions, when executed by the processor, further cause the system to calculate a time-varying control signal based on the corresponding signal and a nonlinear sensitivity relationship between the actual illuminance level and a resulting illuminance level perceived by the human eye; and causing the light emitting element to be illuminated according to the calculated time-varying control signal.

Another aspect of the present disclosure relates to a method of controlling an illuminance level of a light emitting element of a user interface for an electrical device. The method includes storing, by a processor, information defining a signal corresponding to a desired time-varying illuminance level of a light emitting element to be perceived by a human observer, wherein the corresponding signal includes an increasing sinusoidal-based ramp function and a decreasing sinusoidal-based ramp function. The method further includes calculating, by the processor, a time-varying control signal based on the corresponding signal and a nonlinear sensitivity relationship between the actual illuminance level and a resulting illuminance level perceived by the human eye; and causing, by the processor, the light emitting element to be illuminated in accordance with the calculated time-varying control signal.

Another aspect of the present disclosure relates to a method of controlling an illuminance level of a light emitting element of a user interface for an electrical device. The method includes storing, by a processor, a Pulse Width Modulation (PWM) control signal calculated based on stored information defining a signal corresponding to a desired time-varying illumination level of a light emitting element to be perceived by a human observer and a nonlinear sensitivity relationship between an actual illumination level and a resulting illumination level perceived by a human eye, wherein the corresponding signal includes an increasing sinusoidal-based ramp function and a decreasing sinusoidal-based ramp function. The method further includes driving, by the processor, the light emitting element according to the stored control signal.

Drawings

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of embodiments of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments that are within the scope of this disclosure and are therefore not to be considered limiting, for the disclosure may admit to other equally effective embodiments, wherein:

FIG. 1 illustrates three example Pulse Width Modulation (PWM) control signals for a light emitting element in accordance with the principles of the present disclosure;

FIG. 2A illustrates a PWM signal having a linearly increasing duty cycle in accordance with the principles of the present disclosure;

FIG. 2B illustrates how the brightness of a light emitting element controlled with the PWM signal of FIG. 2A is perceived in accordance with the principles of the present disclosure;

FIG. 3 illustrates a non-linear relationship between luminance and psychological brightness in accordance with the principles of the present disclosure;

FIG. 4A illustrates a calculated PWM signal based on a linear increasing ramp function and the nonlinear relationship of FIG. 3 in accordance with the principles of the present disclosure;

FIGS. 4B and 4C illustrate linear increasing and decreasing ramp functions, respectively, according to the principles of the present disclosure;

FIG. 5 illustrates a subjective brightness perception graph of a respiratory light emitting user interface element according to the principles of the present disclosure;

FIGS. 6A and 6B illustrate a sinusoidal-based increasing ramp function and a sinusoidal-based decreasing ramp function, respectively, in accordance with the principles of the present disclosure;

fig. 7A and 7B illustrate scaled versions of the graphs of fig. 6A and 6B, respectively, in accordance with the principles of the present disclosure;

FIG. 8A illustrates a calculated PWM duty cycle signal based on the sinusoidal-based incremental ramp function of FIG. 7A and the nonlinear relationship of FIG. 3 in accordance with the principles of the present disclosure;

FIG. 8B illustrates a calculated PWM duty cycle signal based on the sinusoidal-based incremental ramp function of FIG. 7B and the nonlinear relationship of FIG. 3 in accordance with the principles of the present disclosure;

FIG. 9 illustrates a variation of the graph of FIG. 5 in accordance with the principles of the present disclosure; and is also provided with

Fig. 10A-13 illustrate an electrical device incorporating a light-emitting user interface element in accordance with the principles of the present invention.

Detailed Description

As described above with respect to the light emitting elements of the user interface of the electrical device, turning on and off the LEDs such that they blink may be uncomfortable for some consumers. It is believed that a more gradual change in the illumination level of the LED is more pleasing to some consumers. Embodiments in accordance with the principles of the present disclosure contemplate modulating the illumination level of an LED in a manner that is perceived by the human eye as substantially sinusoidal. As described more fully below, embodiments may include using a combination of the human eye compensation formula with a harmonic-natural-sinusoidal function.

Although one or more example electrical devices are discussed below, they are provided by way of example only to aid in understanding the principles of the present disclosure and are not intended to limit the interpretation or scope of the appended claims. Embodiments in accordance with the principles of the present disclosure include a variety of light emitting elements such as, for example, LEDs, organic LEDs (OLEDs), and illuminated surfaces. Modulating the illumination level of the light emitting element may include turning the element on, increasing the illumination level, maintaining the illumination level, decreasing the illumination level, and turning the element off. As explained in more detail below, PWM signals may be used to control the illumination level of the light emitting element; however, one of ordinary skill will readily recognize that signals having varying voltages (discrete or analog) may also be used to vary the illumination level of the light-emitting element. Further, the user interface of the electrical device may comprise more than one light emitting element, each light emitting element conveying information about a respective state of a different operating characteristic of the electrical device.

As described above, to control the illumination level of the LED, the LED may be driven by a Pulse Width Modulation (PWM) signal, such as, for example, a Pulse Width Modulation (PWM) signal generated by a microcontroller or similar device. Fig. 1 shows three different PWM signals 102, 104, 106. Each signal is periodic with a period 108 of T. In each period, there is a portion 110t _H (wherein the signal has V _CC Voltage level 120) and portion 112t _L (wherein the signal has a voltage level 118 of about 0 volts). Voltage level V _CC Sufficiently above the forward voltage of the LED but low enough to limit the current through the LED so as to prevent damage to the LED. t is t _H The quotient of/T defines the duty cycle of the PWM signal. The duty cycle "k" of PWM corresponds linearly to the LEDIlluminance level, and may be expressed as a fraction between 0 and 1 or an equivalent percentage between 0% and 100%. Thus, signal 102 has a "k"122 equal to 10%, and the illumination level of the LED driven by signal 102 will be that at which the LED is driven by V _CC 10% of the illumination level in the case of continuous or DC signal driving. Signal 104 has a 50% duty cycle k 124 and signal 106 has a 90% duty cycle k 126.

Typically, for PWM signals used to drive LEDs, the switching frequency is so high (i.e., period T is so short) that the human eye does not perceive individual oscillations of the illumination level. The LEDs are perceived as continuously emitting light at a desired illumination level. The minimum speed at which the LED oscillates visible to the human eye varies from person to person. However, a minimum switching frequency of 50Hz or 50 times per second may be typical.

Fig. 2A depicts a graph of how the duty cycle of the PWM signal varies over time along line 202. In particular, the depicted duty cycle increases in a linear fashion from 0 to 1 or from 0% to 100%. Based on the discussion above, the illumination level of the LED driven by the PWM signal should also be increased in a linear fashion with the same slope as line 202. However, fig. 2B shows how the human eye perceives increasing illuminance levels of LEDs driven by PWM signals having the varying duty cycle of fig. 2A. A curve 204 indicates the subjective perception of brightness of the human eye, which curve 204 does not match the line 202. Thus, a user interface with a change in the linearly changing PWM signal is not perceived by the human eye as expected to change in a linearly changing manner, but rather the human eye treats the incremental illumination level of the LED as changing in a non-linear manner.

The brightness of an object is its absolute intensity. Brightness is the perceived brightness of an object, which depends on the brightness of the surrounding environment. Brightness and brightness may be different because human perception of the level of illumination is sensitive to brightness contrast rather than absolute brightness. Thus, brightness is a visually perceived attribute in which the light source appears to be radiant or reflective. Brightness is a perception caused by the brightness of a visual target and may be referred to as mental brightness in the following description. An implementation in accordance with the principles of the present invention considers subjective perception of the human eye by relying on a compensation function based on studies by the CIE (international commission on illumination (International Commission on Illumination)) that relates luminance to psychological brightness. The compensation function is used to adapt the controlled illumination level of the light emitting element, e.g. LED, to the non-linear sensitivity of the human eye. CIE studies correlate luminance values Y ranging from 0 to 1 with psycho-lightness values L ranging from 0 to 100 and are depicted by graph 302 of fig. 3. The graph of fig. 3 is calculated according to the following formula:

If it is903.3. Y

If it isThen->

In the above equation and the following equations, Y varies from 0 to 1 for a particular light emitting element, where the value "1" corresponds to the illuminance level of that particular light emitting element driven by, for example, a PWM control signal having a duty cycle of 100%. In accordance with the principles of the present disclosure, the compensation function is defined as the inverse of the above equation that transforms or converts the L values to Y values, and is defined as:

if it isThen->

If it isThen->

In operation, the L x value may be defined such that the illuminance level of the LED is perceived by the human eye in a desired manner. Based on these L values, a PWM or other type of signal may be determined for controlling the illumination level of the LED. Fig. 4A and 4B illustrate one such example. In this example, a value of l=100 corresponds to a Y value equal to "1", which also corresponds to a duty cycle of 100%. The value l=0 also corresponds to a Y value equal to 0, which also corresponds to a duty cycle of 0%. In fig. 4B, the psychological brightness or subjective brightness perception L of the human eye is defined by graph 404 as increasing linearly with time. Using the compensation function described above, the varying duty cycle of PWM or other type of signal that controls the illumination level of the LED may be calculated. For a given value L (t), a corresponding value Y (t) can be calculated, having a value between 0 and 1, inclusive. The value of Y (t) varying between 0 and 1 is equivalent to the PWM duty cycle k (t), which also varies between 0 and 1 (i.e., between 0% and 100%). In fig. 4A, graph 402 corresponds to the compensation function applied to graph 404 of fig. 4B (i.e., symmetric brightness values L of graph 404 in fig. 4B are converted to brightness values Y using the compensation function described above), and thus depicts how the duty cycle of the PWM signal may be controlled to achieve the perceived linear change in brightness depicted in fig. 4B, for example. Fig. 4C also depicts the perceived linear change in brightness, but in fig. 4C the L-x value decreases from 100 to 0 over time.

A "breathing" light-emitting user interface is a user interface that periodically alternates between increasing and decreasing illumination levels. Thus, the perceived brightness of the light emitting element also alternates periodically between increasing and decreasing the illumination level. One example is depicted in fig. 5. Graph 502 shows how perceived brightness varies over time. Thus, graph 502 defines a signal corresponding to a desired time-varying illuminance level of a light emitting element to be perceived by a human observer. Graph 502 also shows how sharp transition points 504 exist between different portions of graph 502. Due to the presence of the high level region 510 and the low level region 512, the signal or graph 502 may be characterized as a discontinuous increasing ramp function 506 (as shown in fig. 4B) and a decreasing ramp function 508 (as shown in fig. 4C). Using the compensation function described above, the duty cycle of the PWM signal may be calculated, for example, to control the illuminance level of the LED to achieve the desired perceived brightness shown in fig. 5. In accordance with the principles of the present disclosure, one further refinement of the signal or graph 502 may be to smooth the transition point 504.

Instead of L, which varies from 0 to 100 according to the linear ramp of fig. 4B, a sinusoidal-based ramp function may be defined, such as, for example:

For the following

In the above formula, f (t) follows t/t ₀ Increasing from 0 to 1 and changing from 0 to 1 as shown in fig. 6A. Similarly, in the above formula, f (t) follows t/t ₀ Decreasing from 1 to 0 and changing from 1 to 0 as shown in fig. 6B. The sinusoidal-based ramp function may be used to derive an increasing sinusoidal-based ramp function of L x varying from 0 to 100 and a decreasing sinusoidal-based ramp function varying from 100 to 0. Assume a time period t ₀ The incremental sine-based ramp function of FIG. 7A may be based on the time for 0.ltoreq.t/t for an amount of time that the value selected for L increases from 0 to 100 ₀ ≤1，L*(t)＝[100*f(t)]To calculate. In addition, the decreasing sine-based ramp function of FIG. 7B may be based on the ramp function for 1+.t/t ₀ ≥0，L*(t)＝[100*f(t)]To calculate. The graphs or signals of fig. 7A and 7B correspond to how a designer plans the time-varying illumination level of a light-emitting element for perception by a human observer. In other words, the information in the graphs of fig. 7A and 7B defines a respective signal corresponding to a desired time-varying illuminance level of the light emitting element to be perceived by a human observer. However, the control signal for controlling the actual brightness or illuminance level of the light emitting element will be different from the signals of fig. 7A and 7B, because there is the above-described nonlinear sensitivity relationship between the actual illuminance level and the resulting illuminance level as perceived by the human eye, as shown in fig. 3.

As described above with respect to the linear ramp of fig. 4B and 4C, the compensation function may be used to calculate an appropriate PWM signal or other type of control signal to control the illumination level of the LED to achieve a desired perception of the brightness of the LED by the consumer. As also described above, the compensation function may be used to convert the value of the signal corresponding to the desired varying illumination level that the human eye will perceive. The signal or graph resulting from this conversion corresponds to the luminance value Y of how the luminance level of the light emitting element is to be actually controlled. Based on the resulting signal or plot of the luminance value Y, the processor or microcontroller may generate PWM control signals, e.g., at varying duty cycles, to achieve the appropriate actual luminance level of the light emitting element. Fig. 8A and 8B depict duty cycle values corresponding to implementing the sinusoidal-based ramp functions of fig. 7A and 7B, respectively. For a given value L (t), in fig. 7A or 7B, the corresponding value Y (t) may be calculated using the compensation function listed above, such that the corresponding value Y (t) has a value between 0 and 1, inclusive. Thus, the value of Y (t) varying between 0 and 1 is equivalent to the PWM duty cycle k (t), which also varies between 0 and 1 (i.e., between 0% and 100%).

Fig. 9 depicts the result of replacing the linear ramp function in the graph of fig. 5 with increasing and decreasing sine-based ramp functions. As shown, transition point 904 is smoother than sharp transition point 504 of fig. 5. Combining the above-described compensation function with a sine-based ramp function allows for calculating an appropriate duty cycle of the PWM signal or other control signal, which will enable perception of the brightness of the LED in a desired manner. The illumination level Y of the LED is still calculated according to the following equation:

if it isThen->

If it isThen->

However, in the above equation, during the increasing or decreasing ramp portion of the graph or signal 902, the values of L x (t) are those of the sinusoidal-based ramp function discussed above in fig. 7A and 7B, where:

for 0.ltoreq.t/t ₀ ≤1，

In graph 902 of fig. 9, there is a period of time t corresponding to a period in which the duty cycle of the corresponding PWM signal will remain equal to about "zero" such that the LED is perceived as off ₁ . In time period t ₁ During this period, l× (t) =0. For example, period t ₁ And may vary from 0 seconds to hundreds of milliseconds. There is also a period of time t corresponding to a period of time in which the corresponding PWM signal will remain equal to about 100%, such that the LED is perceived as being fully lit ₂ . In time period t ₂ During this period, l× (t) =100. For example, period t ₂ May vary from 0 seconds to hundreds of milliseconds. In addition, t ₁ And t ₂ The values of (c) may be different or they may be the same. In graph 902, there is also a time period t corresponding to a time period in which the corresponding PWM signal will transition from the off state to the fully on state ₀ . In graph 902, there is also a time period t corresponding to a time period in which the corresponding PWM signal will transition from the fully on state to the off state ₃ . Time period t ₀ And time period t ₃ May be equal to or different from each other. t is t ₁ And t ₂ The value of (2) may also be configured as a relative time period, such as, for example, t ₁ (or t) ₂ ) Is (0.8 x t) ₀ )。

As some examples, signal 902 may have a t equal to 200ms ₀ T equal to 0ms ₁ T equal to 1000ms ₂ T equal to 1500ms ₃ See fig. 12. As another example, t of waveform 902 ₀ And t ₃ Can be equal to 1500ms, t ₂ May be equal to 40ms, and t ₁ May be equal to 4000ms, see fig. 12. As another example, waveform 902 may have t equal to 0ms ₁ And t ₂ T equal to 400ms ₀ And t ₃ See fig. 11A. However, in another exemplary waveform 902, t ₀ And t ₃ May be equal to 300ms, e.g., t ₁ Can be equal to 90ms, and t ₂ May be equal to 700ms, see fig. 11B. At no timeIn an example waveform 902 with increasing sinusoidal-based ramp, t ₂ May be a relatively long period of time, t ₃ May be equal to 300ms, see fig. 13.

An apparatus operating in accordance with the principles of the present disclosure may include a processor and a memory in communication with the processor, the memory storing instructions executable by the processor. Further, the instructions, when executed by the processor, cause the device to store information defining a signal corresponding to a desired time-varying illumination level of the light emitting element to be perceived by a human observer, wherein the corresponding signal includes an increasing sinusoidal-based ramp function and a decreasing sinusoidal-based ramp function. The instructions, when executed, further cause the device to calculate a time-varying control signal based on the corresponding signal and a nonlinear sensitivity relationship between the actual illuminance level and a resulting illuminance level perceived by the human eye, and drive the light emitting element to be lit according to the calculated time-varying control signal. Alternatively, the time-varying control signal may be calculated by one or more systems separate from the device. Once the time-varying control signal is calculated, it may be stored in the memory of the device. For example, the time-varying control signal may be stored as a look-up table comprising time-ordered discrete sample values of the calculated time-varying control signal. The processor of the device may read the values from the look-up table and then drive the illumination level of the light emitting elements of the device according to the time-varying control signal.

Fig. 10A illustrates an example electrical device that can include one or more light emitting elements operating in accordance with the principles of the present disclosure. The example razor 1000 of fig. 10A may include a light-emitting heating indicator 1001 and a light-emitting power indicator 1002. In operation, the two indicators 1001, 1002 may operate individually or in synchronization with each other, and may vary in color and illumination levels to convey the operational status of the razor 1000 to a user.

Fig. 10B is a block diagram of functional elements of a razor 1000 or other device that may control light emitting elements of a user interface in accordance with the principles of the present disclosure. Other functional elements of the razor 1000 not related to the light emitting elements are omitted from fig. 10B for clarity and brevity.

The razor 1000 may include a microcontroller 1020 or similar hardware that may retrieve data from the data storage 1026, store data in the data storage 1026, and retrieve executable instructions from the data storage 1026. Microcontroller 1020 also includes a processor 1022 or similar circuitry that can execute executable instructions or initiate executable operations. In particular, processor 1022 may communicate with PWM drive circuitry 1024 to generate PWM control signals 1027. The PWM control signal 1027 drives the light emitting element 1028 such that the illuminance level of the light emitting element 1028 varies according to the PWM control signal.

One of the executable operations that processor 1022 may initiate is to store information defining a signal corresponding to a desired time-varying illumination level of the light emitting element to be perceived by a human observer. As described above, the signal or graph of fig. 5 or 9 corresponds to the desired perceived illuminance behavior of the light emitting element 1028 that the designer of the device 1000 wants to implement. The signals of fig. 5 or 9 are not limited to actual PWM signals or other types of control signals for driving the light emitting elements 1028, but rather represent how the human eye will perceive the illuminance of the light emitting elements 1028 when driving the light emitting elements 1028 with appropriate PWM control signals or other types of control signals. The stored information defining a signal corresponding to a desired time-varying illuminance level of the light emitting element to be perceived by a human observer may be configured in a variety of ways. For example, the information may be a mathematical function describing a graph such as that of fig. 5 or 9, and may be stored in and retrieved from the data storage 1026. In this case, processor 1022 or similar element may use a mathematical function to calculate the value of the corresponding signal. Alternatively, the stored information may be a plurality of discrete samples, for example, corresponding to instantaneous values of the graphs representing fig. 5 or 9, and may be stored in and retrieved from the data storage 1026 by the processor 1022. The stored information may represent a single period of the periodic signal and the sample values may be time-ordered such that the processor 1022 may sequentially retrieve the individual values of the stored information to determine the value of the corresponding signal. The sample values may represent the general profile of a graph or signal (e.g., the graph or signal of fig. 9), but may be enlarged or reduced if desired by the processor 1022. In the particular embodiment described above, the corresponding signal includes an increasing sinusoidal-based ramp function and a decreasing sinusoidal-based ramp function.

Another executable operation that the processor may initiate is to calculate a time-varying control signal based on: a) A corresponding signal defined by the stored information, and b) a nonlinear sensitivity relationship between the actual illuminance level and the resulting illuminance level perceived by the human eye. Fig. 3 shows an example of this type of nonlinear sensitivity relationship. The horizontal axis represents the actual or physical illuminance level of the light emitting element, and the vertical axis represents how the human eye perceives different illuminance levels. In the above example, the compensation function is derived from the relationship shown in fig. 3 and used to calculate the control signal. Because the corresponding signal defined by the stored information is time-varying (examples are depicted by the graphs of fig. 5 or 9), the signal has a plurality of individual values that can be labeled as lx (t), where "t" represents a discrete-time value. The compensation function may be used to calculate a luminance value Y (t) corresponding to the value of L x (t). These luminance values Y (t) may then be converted into corresponding duty cycle values k (t) of the PWM control signal or corresponding voltage values v (t) of the time-varying voltage control signal. The values k (t) or v (t) of the ordered series define a calculated control signal that varies with the time available to drive the light emitting element 1028.

Thus, another one of the executable operations that processor 1022 may initiate includes causing the light emitting element to be illuminated in accordance with the calculated time-varying control signal such that a human observer perceives the illumination level of light emitting element 1028, which generally corresponds to the corresponding signal. Processor 1022 may be configured to directly drive light-emitting elements 1028, or may be configured to control or communicate with separate PWM drive circuitry 1024 to generate PWM signals having appropriate voltage levels and timing characteristics. Processor 1022 may also be configured to control or communicate with other drive circuitry (not shown) to generate control signals (e.g., the varying voltage signal v (t) described above) having appropriate voltage levels and timing characteristics.

Fig. 11A shows an example of how different light-emitting elements 1001 and 1002 can operate. Horizontal timeline 1104 provides an example plot of information defining a signal corresponding to a desired time-varying illuminance level of heating indicator 1001 to be perceived by a human observer, and horizontal timeline 1106 provides an example plot of information defining a signal corresponding to a desired time-varying illuminance level of power indicator 1002 to be perceived by a human observer. Once the razor 1000 is turned on 1108, the warming period 1110 may begin and may last for about 2 seconds, for example. During this time, the power indicator 1002 is fully illuminated and the heating indicator 1001 breathes at a rate of, for example, about 0.5 seconds. When the razor 1000 reaches its ready-to-use state (1112) and its in-use state (1114), both the illuminated indicator 1001 and the illuminated indicator 1002 may remain continuously illuminated. When the razor 1000 is turned off, both the illuminated indicator 1001 and the illuminated indicator 1002 may then be turned off. In fig. 11A, a charging stand 1102 is depicted that is connectable with the razor 1000.

Fig. 11B shows how the illuminated indicator 1001 and the illuminated indicator 1002 may be controlled to indicate different operational states of the razor 1000. Horizontal timeline 1150 provides an example plot of information defining a signal corresponding to a desired time-varying illuminance level of heating indicator 1001 to be perceived by a human observer, and horizontal timeline 1152 provides an example plot of information defining a signal corresponding to a desired time-varying illuminance level of power indicator 1002 to be perceived by a human observer. During conditions of low battery state of charge (1148), the heating indicator 1001 is fully illuminated, and the power indicator 1001 blinks at a rate of, for example, about 1.0 seconds.

Fig. 12 shows one example of how light emitting elements 1001 and 1002 may operate when razor 1000 is connected to a charging stand 1102. In particular, the charging dock 1102 may include its own light emitting element 1202, which may be a charge indicator. Horizontal timeline 1204 provides an example plot of information defining a signal corresponding to a desired time-varying illuminance level of heating indicator 1001 to be perceived by a human observer, and horizontal timeline 1206 provides an example plot of information defining a signal corresponding to a desired time-varying illuminance level of power indicator 1002 to be perceived by a human observer. Horizontal timeline 1208 provides an example graph of information defining a signal corresponding to a desired time-varying illumination level of charge indicator 1202 to be perceived by a human observer.

In the example of fig. 12, the heating indicator 1001 may remain unlit during all of the periods shown, such as when the razor 1000 is placed on a charger (1210), when the razor 1000 is charging (1212), and when the razor is fully charged (1214). In accordance with the principles of the present disclosure, a PWM or other type of control signal may be calculated that causes both power indicator 1002 and charge indicator 1202 to operate as a lighted breathing user interface. The PWM signal may, for example, cause the illumination levels of both elements 1002 and 1202 to change such that they are perceived as changing, as shown in fig. 9 and horizontal time line 1206 and horizontal time line 1208. In the example of fig. 12, the respiration rate is about 3 seconds. Fig. 12 also shows that when the razor 1000 is placed on the charging stand 1102, the synchronization pulse may be sent to the processor or controller that generates the PWM control signal for the power indicator 1002, and may also be sent to the processor or controller that generates the PWM control signal for the charge indicator 1202.

Fig. 13 shows that the same light emitting element may have different colors at different times. In fig. 13, horizontal timeline 1302 provides an example plot of information defining a signal corresponding to a desired time-varying illuminance level of heating indicator 1001 to be perceived by a human observer, and horizontal timeline 1304 provides an example plot of information defining a signal corresponding to a desired time-varying illuminance level of power indicator 1002 to be perceived by a human observer. During the time when the user presses the button 1003 to enter the first heating mode (1310), both the light-emitting indicator 1001 and the light-emitting indicator 1002 may be fully lit and red in color. During the first heating mode (1312), both indicator 1001 and indicator 1002 may remain fully lit but yellow in color. During the time when the user presses button 1314 again to enter the second heating mode, both indicator 1001 and indicator 1002 may remain fully illuminated and yellow in color. However, when the second heat mode (1316) is reached, the colors of the lighted light emitting element 1001 and light emitting element 1002 may change to red.

The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various aspects of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). Furthermore, while the flow diagrams have been discussed and illustrated with respect to a particular sequence of events, it will be appreciated that changes, additions and omissions may be made to the sequence without materially affecting the operation of the disclosure. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

As will be appreciated by one of ordinary skill in the art, aspects of the present disclosure may be illustrated and described herein in any of a number of patentable categories or contexts, including any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof. Thus, aspects of the present disclosure may be implemented in complete hardware, complete software (including firmware, resident software, micro-code, etc.), or in combination with hardware and software implementations that may be referred to herein collectively as a "circuit," module, "" component, "or" system. Furthermore, aspects of the present disclosure may take the form of a computer program product embodied in one or more computer-readable media having computer-readable program code embodied thereon.

Any combination of one or more computer readable media may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. The computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable storage medium would include the following: portable computer diskette, hard disk, random Access Memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), suitable optical fiber with a repeater, portable compact disc read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

Computer program code for carrying out operations for aspects of the present disclosure may be written in any combination of one or more programming languages, including an object oriented programming language such as JAVA, SCALA, SMALLTALK, EIFFEL, JADE, EMERALD, C ++, CII, vb.net, PYTHON and the like; conventional programming languages, such as "c" programming language, visualbasic, FORTRAN 2003, PERL, COBOL 2002, PHP, ABAP; dynamic programming languages such as PYTHON, RUBY, and GROOVY; or other programming language. The program code may execute entirely on the user's computer or device.

Aspects of the present disclosure are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the disclosure. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable instruction execution apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable medium that, when executed, can instruct a computer, other programmable data processing apparatus, or other devices to operate in a particular manner such that the instructions, when stored in the computer-readable medium, produce an article of manufacture including instructions that, when executed, cause the computer to implement the functions/acts specified in the flowchart and/or block diagram block or blocks. The computer program instructions may also be loaded onto a computer, other programmable instruction execution apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

The representative embodiments of the present disclosure described above may be described as follows:

A. a method of controlling an illuminance level of a light emitting element for a user interface of an electrical device, the method comprising:

storing, by a processor, information defining a signal corresponding to a desired time-varying illuminance level of the light emitting element to be perceived by a human observer, wherein the corresponding signal comprises an increasing sinusoidal-based ramp function and a decreasing sinusoidal-based ramp function;

calculating, by the processor, a time-varying control signal based on the corresponding signal and a nonlinear sensitivity relationship between an actual illuminance level and a resulting illuminance level perceived by a human eye; and

causing, by the processor, the light emitting element to be illuminated in accordance with the calculated time-varying control signal.

B. The method of paragraph a, wherein the corresponding signal is periodic and is comprised of a plurality of time periods.

C. The method of paragraph a or paragraph B, wherein the corresponding signal comprises:

a low level value from which the increasing sinusoidal-based ramp function increases to a high level value, and from which the decreasing sinusoidal-based ramp function decreases to the low level value.

D. The method of any of paragraphs a-C, wherein the nonlinear sensitivity relationship comprises a relationship between luminance and mental brightness.

E. The method of any one of paragraphs a-D, wherein the calculated time-varying control signal is calculated by converting the corresponding signal using a compensation function, wherein the compensation function is based on the nonlinear sensitivity relationship between the actual luminance level and a resulting luminance level perceived by the human eye, and comprises:

if it isThen->

If it isThen->

Wherein the method comprises the steps of

Y is the calculated time-varying control signal; and is also provided with

L is the corresponding signal.

F. The method of any one of paragraphs a-E, wherein the increasing ramp function and the decreasing ramp function vary over time t in a manner proportional to:

for the following

G. The method of any one of paragraphs a-F, wherein the light emitting element comprises one of a Light Emitting Diode (LED) or a light emitting surface.

H. The method of any one of paragraphs a through G, wherein the stored information comprises a formula for calculating the corresponding signal.

I. The method of any of paragraphs a through H, wherein the stored information comprises a plurality of discrete sample values representing a time ordering of the corresponding signals.

J. A system for controlling the illuminance level of a light emitting element for a user interface of an electrical device

A system, the system comprising:

a processor; and

a memory in communication with the processor, the memory storing instructions that, when executed by the processor, cause the system to:

storing information defining a signal corresponding to a desired time-varying illuminance level of the light emitting element to be perceived by a human observer, wherein the corresponding signal comprises an increasing sinusoidal-based ramp function and a decreasing sinusoidal-based ramp function;

calculating a time-varying control signal based on the corresponding signal and a nonlinear sensitivity relationship between an actual illuminance level and a resulting illuminance level perceived by a human eye; and

causing the light emitting element to be illuminated according to the calculated time-varying control signal. K. The system of paragraph J, wherein the corresponding signals are periodic and are formed by a plurality of

The time period is constituted.

The system of paragraph J or paragraph K, wherein the corresponding signals comprise:

A system according to any of paragraphs J to L, wherein the nonlinear sensitivity relationship comprises a relationship between luminance and psychological brightness.

N. the system of any of paragraphs J through M, wherein the calculated time-varying control signal is calculated by converting the corresponding signal using a compensation function, wherein the compensation function is based on the actual illuminance level and the resulting illuminance perceived by the human eye

The nonlinear sensitivity relationship between levels, and comprises:

if it isThen->

If it isThen->

Wherein the method comprises the steps of

Y is the calculated time-varying control signal; and is also provided with

L is the corresponding signal.

The system of any one of paragraphs J to N, wherein the increasing ramp function and the decreasing ramp function vary over time t in a manner proportional to:

for the following/>

The system of any one of paragraphs J-O, wherein the light emitting element comprises one of a Light Emitting Diode (LED) or a light emitting surface.

A system according to any of paragraphs J through P, wherein the stored information comprises a formula for calculating the corresponding signal.

The system of any one of paragraphs J through Q, wherein the stored information comprises a plurality of discrete sample values representing a time ordering of the corresponding signals.

S. a method of controlling an illuminance level of a light emitting element of a user interface for an electrical device, the method comprising:

storing, by the processor, a Pulse Width Modulation (PWM) control signal, the pulse width modulation

A (PWM) control signal is calculated based on stored information defining a signal corresponding to a desired time-varying illumination level of the light emitting element to be perceived by a human observer and a nonlinear sensitivity relationship between an actual illumination level and a resulting illumination level perceived by a human eye, wherein the corresponding signal comprises an increasing sinusoidal-based ramp function and a decreasing sinusoidal-based ramp function; and

driving the light emitting element with the stored PWM control signal by the processor.

T. the method of paragraph S, wherein the stored PWM control signal comprises a look-up table.

The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Rather, unless otherwise indicated, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as "40mm" is intended to mean "about 40mm".

Each document cited herein, including any cross-referenced or related patent or patent application, and any patent application or patent for which this application claims priority or benefit from, is hereby incorporated by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to the present invention, or that it is not entitled to any disclosed or claimed herein, or that it is prior art with respect to itself or any combination of one or more of these references. Furthermore, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.

While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims

1. A method of controlling an illuminance level of a light emitting element (1028) for a user interface of an electrical device (1000), the method comprising:

storing, by a processor (1022), information defining a signal corresponding to a desired time-varying illuminance level of the light emitting element to be perceived by a human observer, wherein the corresponding signal includes an increasing sinusoidal-based ramp function and a decreasing sinusoidal-based ramp function;

causing, by the processor, the light emitting element to be illuminated in accordance with the calculated time-varying control signal;

wherein the calculated time-varying control signal is calculated by converting the corresponding signal using a compensation function, wherein the compensation function is based on the nonlinear sensitivity relationship between the actual luminance level and a resulting luminance level perceived by the human eye, and comprises:

If it isThen->

Wherein the method comprises the steps of

Y is the calculated time-varying control signal; and is also provided with

L is the corresponding signal.

2. The method of claim 1, wherein the corresponding signal is periodic and is comprised of a plurality of time periods.

3. The method of claim 1, wherein the corresponding signal comprises:

4. The method of claim 1, wherein the nonlinear sensitivity relationship comprises a relationship between luminance and mental brightness.

5. The method of claim 1, wherein the increasing ramp function and the decreasing ramp function vary over time t in a manner proportional to:

for the following

6. The method of claim 1, wherein the light emitting element (1028) comprises one of a light emitting diode or a light emitting surface.

7. The method of claim 1, wherein the stored information comprises a formula for calculating the corresponding signal.

8. The method of claim 1, wherein the stored information comprises a plurality of discrete sample values representing a time ordering of the corresponding signals.

9. A system for controlling an illuminance level of a light emitting element (1028) for a user interface of an electrical device, the system comprising:

a processor (1022); and

causing the light emitting element to be illuminated according to the calculated time-varying control signal;

if it isThen->

If it is Then->

Wherein the method comprises the steps of

Y is the calculated time-varying control signal; and is also provided with

L is the corresponding signal.

10. The system of claim 9, wherein the corresponding signal is periodic and is comprised of a plurality of time periods.

11. The system of claim 9, wherein the corresponding signal comprises:

12. The system of claim 9, wherein the nonlinear sensitivity relationship comprises a relationship between luminance and mental brightness.

13. The system of claim 9, wherein the increasing ramp function and the decreasing ramp function vary over time t in a manner proportional to:

for the following